InfoPath Dev

I have a form that I am having problems with trying to get it to show a result. Example Field 1 - ((Field 1/Field 2)*Field 3)). It should store the result of that formula. I can't get the formula to take. Any help would be much appreciated. TIA. 

When I went back in and deselected the checkbox for setting to run when the form opens then it takes away all the drop down selections in my box to select from. This is what happens. I have a drop down box that has say all the cities for Florida, well all the cities show up below the box and if I select a city then it only shows that particular ...

Good afternoon, I am trying to create a new form and to start. I want to have a drop down box that gives you a list of lets says companies. Once a company is selected then I want the query to run and return the appropriate address for that particular company. Right now, I have followed a video on you tube and done everything int he same sequence. ...